Field of the Invention
The present invention concerns novel organosilicon polymers and a method for their manufacture, more specifically poly(silethynylenedisiloxane) having alternating silethynylene units and siloxane units, such that the main skeleton of the polymer has repeating units of the formula --SiC.tbd.CSiOSiO--.
There have been numerous reports of polymers with mainchain repeating units containing an ethynylene group (--C.tbd.C--) bonded to a silicon atom. Also, there have been many reports of polymers having both a silicon-bonded ethynylene group and a siloxane group in the main-chain repeating units. For example, British Patent No. 2234517 disclosed a method for the manufacture of random copolymers of the --SiC.tbd.C-- unit and --SiO-- unit using a lithium catalyst.
However, such conventional polymers lack regularity in structure. In particular, there have not been any reports on polymers consisting of completely alternating silethynylene unit and siloxane unit, such as --SiC.tbd.CSiOSiO--, as the main skeleton. Here, it is an objective of the present invention to provide polymers with completely alternating silethynylene units and siloxane units, such as --SiC.tbd.CSiOSiO--, as the main skeleton.
As a result of an intense investigation of ways to achieve such objectives, we have succeeded in synthesizing poly(silethynylenedisiloxane) with repeating units represented by the formula: EQU --R.sup.1 R.sup.2 SiC.tbd.CSiR.sup.3 R.sup.4 OSiR.sup.5 R.sup.6 O--(I)
In the formula, R.sup.1 -R.sup.6 independently represent hydrogen atoms, alkyl groups, aryl groups, or alkenyl groups.